1. Field of the Invention
The present invention relates generally to sprayable adhesive compositions used as spray-type adhesives, and more particularly, to a sprayable adhesive composition making it possible to repeatedly affix and strip a surface coated with the adhesive composition to and from a surface to be affixed and making it difficult to cause adhesive transfer of the adhesive composition to the surface to be affixed when the above surface coated with the adhesive composition is stripped from the surface to be affixed.
Conventionally, various spray-type adhesives have been commercially available. Furthermore, in recent years, spray-type adhesives having adhesive properties which allow affixing and stripping to and from a surface of paper many times have been commercially available.
One example of adhesive compositions usable as the above described spray-type adhesives is disclosed in British Patent No. 1,250,261. The specification discloses a sprayable adhesive composition constructed by dispersing in a suitable organic solvent and aerosol propellant an adhesive substance composed of a copolymer, which contains a (meth)acrylic ester and a monomer copolymerizable with the (meth)acrylic ester and is crosslinked by a crosslinker.
Furthermore, another example of adhesive compositions usable as the spray-type adhesives is disclosed in U.S. Pat. No. 453,825. The specification discloses a spray-type adhesive using an elastomer composed of a butadienacrylonitrile copolymer.
In any of the above described conventional sprayable adhesive compositions, a bulk-shaped copolymer and an elastomeric polymer are crushed into particles, the adhesive particles obtained are caused to swell by a solvent, and an aerosol container is filled with the adhesive particles along with an aerosol propellant.
In spray-type adhesive superior in adhesive properties to a surface of paper out of the conventional spray-type adhesives, however, when a substrate coated with the adhesive is affixed to a surface of paper, the surface of paper to which the substrate is affixed may, in many cases, be torn off in the case of stripping. That is, the adhesive power of the adhesive is high, so that the surface of paper to which the substrate is affixed may, in many cases, be damaged.
On the other hand, an adhesive composition containing adhesive microspheres exhibiting superior removability has been proposed in recent years as a removable adhesive composition (for example, Japanese Patent Laid-Open Gazette No. 260973/1988). However, the microspherical adhesives which have conventionally existed are ones, which are used for coating a substrate, such as "Post-it note pad" (trade name) manufactured by Minesota Mining and Manufacturing Company in the United States. No microspherical adhesives used as a sprayable adhesive composition have existed yet.